Socket structure



Jan. 5, 1960 R. M. HELLER 2,920,302

SOCKET STRUCTURE Filed Oct. 28, 1957 INVENTOR.

ROBERT M. HELLER ATTORNEYS United States Patent SOCKET STRUCTURE Robert M. Heller, Birmingham, Mich., assignor to Watts Electric & Mfg. Co., Birmingham, M1ch., a corporation of Michigan Application October 28, 1957, Serial No. 692,683 7 3 Claims. (Cl. 33993) This invention relates generally to electrical receptacles, and refers more particularly to electric bulb sockets.

One of the essential objects of the invention is to provide a bulb socket with means capable of protecting the electric bulb and filament portion thereof from destruction or premature failure by absorbing any vibrations and shocks to which such bulb may be subjected while in use.

Another object is to provide a bulb socket with spring means capable of holding the base portion of the electric bulb against one side wall of said socket or under compression or pressure while the electric bulb is in use.

Another object is to provide a bulb socket with spring means capable of frictionally engaging and automatically holding the base portion of the electric bulb against accrdental movement or displacement when inserted into said socket.

Another object is to provide a bulb socket with holding means of the type mentioned formed from spring steel capable of retaining its spring qualities after repeated use and capable of accepting automatically the normal variations of socket diameters and of bulb base diameters prevalent with the dimensional tolerances established by the manufacturers.

Another object is to provide a bulb socket with a holding spring that will compensate for any irregularities in the diameters of the bulb sockets or of the bulb bases to which the holding spring is applied.

Another object is to provide a bulb socket that is simple in construction, economical to manufacture, and eflicient in operation.

The foregoing as well as other objects will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a longitudinal sectional view through a bulb socket and holding spring embodying my invention, and showing an electric light bulb applied thereto.

Figure 2 is a fragmentary elevational view of the bulb socket and electric bulb illustrated in Figure 1.

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 1.

Figure 4 is a sectional view taken substantially on the line 4-4 of Figure 1.

Figure 5 is a perspective view of the holding spring.

Figure 6 is an end view of the plasticboot.

In the drawing, A is the bulb socket, B is the electric bulb, and C is the holding spring embodying my invention.

As shown, the bulb socket A has a tubular shell 10 and a short tubular attaching member 11. shell 10 and attaching member 11 are formed from sheet metal and are rigidly secured together. Preferably the shell 10 is provided at one end or mouth thereof with an annular outwardly projecting flange 12 having an open return bent marginal flange 13, and is provided at its other end with an-annular outwardly projecting open return bent flange 14 of substantially O-shape in Both the conductors.

spectively of this boot are upon the inner and outer sides cross section. The attaching member 11 has at one end thereof an annular laterally projecting flange 15 extending between and clamped by the flanges 12 and 13 respectively of the shell. Such attaching member 11 is adapted to extend through an opening in a metal instrument panel or the like (not shown) and has a free end that is adapted to be upset or return bent to provide an outwardly projecting flange, similar to the flange '15, to

overlie and be pressed against the opposite surface of said panel. Any suitable means such as a ring of insulating material (not shown) may be employed to surround the attaching member 11 between the instrument panel and the upset or return bent flange mentioned to providean effective seal between such parts.

The electric bulb B is a standard type having a cylin-Z drical base portion 20, a glass bulb portion 21, an electric filament portion 22, and one or more electric terminals 23 connected by wiring (not shown) extending through the base portion 20 to the filament portion 22.

As usual, the base portion 20 of the bulb is provided at diametrically opposite sides thereof with radially ex-' tending lugs or projections 24 that are detachably engage- One or more electrical conductors (not shown) are adapted to extend from a suitable source through the opening provided by the annular flange 14 into the lower end of the shell 10 and are provided at their free ends within the shell with electric terminals (not shown) adapted to be engaged by the terminals 23 of the electric bulb when the base portion 20 of said bulb is inserted into the socket. Any suitable means (not shown) may be employed within the shell 10 to hold the terminal portions of the electrical conductor in proper position to be engaged by the terminals 23 of the electric bulb B In the present instance, a resilient boot D cooperates with the shell 10 to form an enclosure for vthe electrical As shown, tubular portions 30 and 31 reof said shell 10, while a relatively thick annular part 32 of the inner tubular portion 30 is Within the open return bent flange 14 of said shell and serves to interlock or' anchor the boot D with said shell 10. Such inner tubular portron 30 extends through the opening provided by the annular flange 14 of the shell and constitutes an endwise projection or continuation of the body portion'33 of the boot. The free end portion 34 of the boot is initially oval or elongated in shape, as illustrated in Figure 6, and may be crrmped upon and fused or heat sealed with the' usual rnsulatrng coverings of the electrical conductors to The holding spring C is a one-piece element and is formed from spring steel. As shown, this spring has a flat annular portion 40 extending between and clamped by the flanges 12 and 15 respectively of the shell 10 and attaching member 11 and has at the inner edge of said annular portion 40 an integral substantially L-shaped strip or narrow arm portion 41 terminating in an outwardly offset finger portion 42. The short arm 43 of the L-shaped strip portion projects edgewise in an inward direction from the annular portion 40, while the long arm 44 of the strip portion is bowed or arched slightly and is disposed at substantially right angles to the annular portion 40. Such bowed portion 44 is engageable Patented Jan. 5, 1960 with one side of the base portion 20 of the bulb B when the latter is inserted into the socket. The finger portion 42 is relatively short and straight and is engageable with a longitudinally extending groove or channel 45 substantially corresponding in width to the width of the finger portion 42 and provided by a similarly shaped outwardly oflset or embossed portion 46 of the shell at one side thereof. Thus this finger portion 42 is substantially in terlocked with the shell 10 and cannot swing or move circumfcrentially thereof, even if the clamped connection between the flanges 12 and 15 and the annular portion 40 of the spring should be loose.

It will also be noted that the annular portion 40 of the spring is outside the J-shaped grooves 25, and that the strip portion 42 of the spring is intermediate the J-shaped grooves 25, hence neither the annular portion 40 nor the strip portion 42 of the spring will ever interfere with the engagement of the lugs 24 on the base portion of the bulb with such grooves when the bulb B is either inserted into or withdrawn from the socket.

In use, when the base portion 20 of the electric bulb is inserted into the socket, the lugs 24 on the base portion 20 will engage the J-shaped grooves 25, while the spring strip 41 of the spring C will frictionally engage one side of said base portion 20 and will elfectively hold the same tight against the opposite side of the shell 10. Consequently, when the base portion 2% of the bulb is inserted into the socket, it will be automatically engaged and held under compression and thereby will be held against accidental movement or displacement. Thus the bulb B and filament portion 22 thereof will be effectively protected against vibration and shock that otherwise might cause destruction or premature failure of such elements. The spring C will also be held against displacement and will retain its spring qualities after repeated use. Also, the spring strip 41 will compensate for any irregularities in the diameters of the socket shells 143 or of the bulb bases 20 to which the spring strip 41 is applied. Thus the spring C is capable of accepting automatically the normal variations of socket diameters and of bulb base diameters prevalent with the dimensional tolerances established by the manufacturers.

What I claim as my invention is:

1. An electric bulb socket comprising an elongated tubular shell adapted to receive the cylindrical base portion of an electric bulb, said shell having an inwardly opening channel in the inner wall at one side of said shell extending longitudinally from the mouth end of said shell toward the opposite end thereof, and means for holding the cylindrical base portion of a bulb under pressure against the inner side wall of said shell at the opposite side thereof, said means including a holding spring member of integral one-piece construction which I said channel and being longitudinally bowed radially inwardly so that its midportion is yieldably engageable with the base portion of said bulb to hold it under pressure against the inner wall of said shell at said opposite side thereof, the free end of said spring strip portion being outwardly offset with respect to said midportion to extend within and slidably engage said channel to reinforce said spring strip portion, said channel substantially corresponding in width to said free end to lock said holding spring member against rotation relative to said shell,

2. An electric bulb socket comprising an elongated tubular shell adapted to receive the cylindrical base portion of an electric bulb, said shell being formed to provide an inwardly opening annular groove about its mouth end and having an inwardly opening channel extending longitudinally from said groove toward the opposite end of said shell, and means for holding the cylindrical base portion of a bulb under pressure against the inner wall of said shell at the side thereof opposite said channel, said means comprising a holding spring member of integral one-piece construction formed of resilient material, said holding spring member being separate from said shell and having a flat ring portion clamped within said groove in concentric relation to said shell with its inner edge spaced radially outwardly of the inner wall of said shell and adapted to encircle the base portion of said bulb, said member having an elongated resilient spring strip portion integrally joined at one end to the inner edge of said ring portion and extending at substantially right angles thereto in a direction toward the opposite end of said shell and along the inner wall thereof, said spring strip portion being disposed in registration with said channel and being longitudinally bowed radially inwardly so that its midportion is yieldably engageable with the base portion of said bulb to hold it under pressure against the inner wall of said shell at said opposite side thereof, the free end of said spring strip portion being outwardly offset with respect to said midportion to extend Within and slidably engage said channel to reinforce said spring strip portion, said channel substantially corresponding in width to said free end to lock said holding spring member against rotation relative to said shell.

3. An electric bulb socket as in claim 2, said shell having longitudinal J-shaped slots extending from said groove at the mouth end thereof for receiving locking lugs on the base portion of said bulb, said slots being spaced circumferentially from said channel and the spring strip portion therein, and the inner edge of said ring portion being spaced radially outwardly from said locking lugs so that the insertion and removal of said lugs relative to said slots may be free of and without interference with said holding spring member.

References Cited in the file of this patent UNITED STATES PATENTS 1,261,789 Douglas Apr. 9, 1918 1,514,314 Douglas Nov. 4, 1924 1,678,138 Douglas July 24, 1928 2,494,845 Wagstaff Jan. 17, 1950 2,664,550 Howard Dec. 29, 1953 2,710,386 Hall June 7, 1955 at u 

